function y = tax(x)
%TAX returns the amount of income taxes for an ordinary income x
y=zeros(size(x));
y(x>21)=0.1*(x(x>21)-21);
y(x>39)=0.15*(x(x>39)-39)+1.8;
y(x>96)=0.25*(x(x>96)-96)+10.35;
end

